#include <stdio.h>

int sum(int x, int y);

/**
 * 一个返回值函数
 */
int main() {

	int x = 1, y = 2;

	printf("x = %d, y = %d\n", x, y);

	printf("sum(x, y) = %d\n", sum(x, y));
	
}

int sum(int x, int y) {
	return x + y;
}
